Process of making concrete piles.



-PATENTED JULY 7, 1903. F. SHUMAN.

APPLIOATION FILED APR. 23. 1903.

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PROCESS POR MAKING CONCRETE PILES.

No MODEL.

UNITED STATES Patented J'uly 7, 1903. l

PATENT OEEICE.

FRANK SHUMAN, OF PHILADELPHIA, PENNSYLVANIA.

SPECIFICATION forming part of Letters Patent N o. 733,287, dated July 7, 1903.

Application iiled April 23, 1903. Serial No. 153,974. (No model.)

To all whom it may concern;

Be it known that I, FRANK SHUMAN, acitizen of the United States, residing in Philadelphia, Pennsylvania, have invented an Improved Process of Making Concrete Piles, of which the following is a specification.

My invention relates to that method of forming piles of concrete or cement which consists in first driving a preparatory pile into the ground and then withdrawing'said preparatory pile and filling the opening formed thereby with concrete or cement in iiuid or plastic form, which when it becomesset forms the permanent pile.

The object of my invention is to provide for driving or withdrawing the preparatory pile with the exercise of much less power than is required when piles of this class as heretofore constructed are used.

In the accompanying drawings, Figure lis a sectional view illustrating the method of forming the opening in the ground by means of the preparatory pile in accordance with my invention, and Fig. 2 is a similar view showing the preparatory pile removed and the opening filled with concrete to form the permanent pile.

For the purpose of forming in the ground openings for the reception of concrete or cement to constitute a permanent pile the use of an ordinary wooden or metal preparatory pile of cylindrical form or tapering inwardly from top to bottom is objectionable for the reason that the frictional hold of the earth upon the sides of the same is such that the pile cannot be driven beyond a limited distance without the exercise of destructive force and cannot be withdrawn after being driven without the exercise of still greater force, frictional hold of the earth upon the pile being now assisted by atmospheric pressure, owing to the fact that the withdrawal of the pile tends to create a partial vacuum in the opening left thereby. For this reason various forms of collapsible piles have been proposed; but such piles, owing to their sectional character, are necessarily limited in strength and, moreover, do notl overcome the objection of resistance to the frictional hold of the earth thereupon while they are being driven. When the pile tapers inwardly from top to bottom,

there is the same resistance to the driving of the pile and the resistance to the withdrawal of the pile is also excessive, because owing to the atmospheric pressure the earth is caused to cling firmly to the pile, so as to increase the difficulty of starting the pile and retard its movement for some time after it is started. In carrying out my invention, therefore, I displace the earth at and near the point of the preparatory pile to a greater extent than the diameter of said pile, thereby freeing the pile, except as to a limited area at and near the point, from any material frictional contact with the walls of the opening formed thereby, thus not only facilitating the driving of the pile, but also the withdrawal of the same.

On reference to Fig. l it will be observed that the preparatory pile l is in the form of a metal tube, although it may be a solid pile of wood or metal, if desired, this pile being provided at the top with a suitable driving*- head 2 and at the bottom with a point 3, which is of so much greater diameter than the pile l that there is no likelihood of the latter coming in contact to any material extent with the walls of the opening formed by driving the pile. The point is reduced in diameter at the top, so as to provide a shoulder for engagement with the lower end of the pile, and this reduced portion of the point may, if desired, be secured to the lower end of the pile by rivets 4 or other suitable fastenings, or the pile and its point may be in one piece, if desired. The point 3 has a tapered lower end and also, by preference, tapers from its portion of greatest diameter inwardly tothe shoulder upon which rests the lower end of the pile l, so that no abrupt shoulders are presented to the earth either in driving the pile or withdrawing the point. After the preparatory pile has been withdrawn the opening is iilled with concrete or cement and the latter is permitted to remain without disturbance until it becomes set, so as to form the permanent pile 6, as shown in Fig. 2.

Having thus described my invention, I claim and desire to secure by Letters Patentl. The method of making concrete piles which consists in providing a pile with an enlarged head, driving said pile to displace the IOO earth and thereby forming a hole larger than concrete to remain without disturbance until the pile-stem, withdrawing the pile, and afit becomes set, substantially as specified.

terward filling the hole with concrete, sub- In testimony whereof I have signed my stantially as specified. name to this specification in the presence of 5 2 The Inethod of making concrete piles two subscribing witnesses.

which consists in providing a pile with an en- FRANK SHUMAN larged head, driving said pile to displace the I earth, and thereby form a hole larger than Witnesses:

the pile-stem, withdrawing the pile, lling F. E. BECHTOLD, 1o the hole with concrete, and permitting said JOS. H. KLEIN. 

